--- ./nx-X11/programs/Xserver/GL/mesa/X/xf86glx.c.X.original	2015-02-13 14:03:44.680442769 +0100
+++ ./nx-X11/programs/Xserver/GL/mesa/X/xf86glx.c	2015-02-10 19:13:14.340665851 +0100
@@ -71,6 +71,10 @@
 
 #include "glcontextmodes.h"
 
+#ifdef NXAGENT_SERVER
+#include "../main/WSDrawBuffer.h"
+#endif
+
 /*
  * This structure is statically allocated in the __glXScreens[]
  * structure.  This struct is not used anywhere other than in
@@ -95,6 +99,36 @@
     NULL                  /* WrappedPositionWindow is overwritten */
 };
 
+#ifdef NXAGENT_SERVER
+WSDrawBufferPtr pWSDrawBuffer = NULL;
+
+void AddWSDrawBuffer(GLframebuffer *mesa_buffer)
+{
+  WSDrawBufferPtr prevWSDB;
+  WSDrawBufferPtr newWSDB;
+  WSDrawBufferPtr p;
+
+  prevWSDB = NULL;
+  newWSDB = NULL;
+  p = pWSDrawBuffer;
+  while (p != NULL) {
+    prevWSDB = p;
+    if (prevWSDB -> DrawBuffer == mesa_buffer) {
+      return;
+    }
+    p = p -> next;
+  }
+  newWSDB = malloc(sizeof(WSDrawBufferRec));
+  newWSDB -> DrawBuffer = mesa_buffer;
+  newWSDB -> next = NULL;
+
+  if (pWSDrawBuffer == NULL)
+    pWSDrawBuffer = newWSDB;
+  else
+    prevWSDB -> next = newWSDB;
+}
+#endif
+
 void *__glXglDDXScreenInfo(void) {
     return &__glDDXScreenInfo;
 }
@@ -748,6 +782,10 @@
     __MESA_buffer buf = (__MESA_buffer)glPriv->private;
     __GLXdrawablePrivate *glxPriv = (__GLXdrawablePrivate *)glPriv->other;
 
+#ifdef NXAGENT_SERVER
+    AddWSDrawBuffer(& (buf -> xm_buf -> mesa_buffer) );
+#endif
+
     /* Destroy Mesa's buffers */
     if (buf->xm_buf)
 	XMesaDestroyBuffer(buf->xm_buf);
@@ -757,7 +795,7 @@
     glPriv->frontBuffer.resize = buf->fbresize;
 
     __glXFree(glPriv->private);
-    glPriv->private = NULL;
+    glPriv->private = NULL; 
 }
 
 __GLinterface *__MESA_createContext(__GLimports *imports,